BOSTON – John Valentin made two admissions Saturday night after racking up five RBI in the Red Sox 13-1 trashing of the Yankees in Game 3 of the ALCS.

The Red Sox third baseman, after blasting a 2-2 Roger Clemens fastball into the net above the Green Monster, admits he has been in a zone in these playoffs. This is like Alan Greenspan acknowledging his speeches have an impact on the market.

And Valentin also admitted that he has played this season with a painful left knee that will require surgery after the season to alleviate patella tendonitis. At times the knee was so aggravated and sore that Valentin wondered if he should not be in the lineup.

“This season has been tough,” said Valentin, who went 2-4 with a double in the 9-2 loss to the Yankees last night in Game 4. “I really didn’t say anything about it. I just kept playing. Everyone in this clubhouse is hurting so for me to say my knee hurts and that’s why I’m not playing well, or I don’t think I should play anymore, it just doesn’t work that way.”

Valentin has been working some magic this fall. The kind of magic that an underdog team needs if it’s going to work a miracle. The kind of magic that can make a hometown hero out of a player.

We go back to Game 3 of the ALDS against the Indians with the Sox trailing 2-0 in the series and the score tied, 2-2 in the sixth. Valentin steps to the plate in Fenway and smacks a solo home run. He plays hero again in the seventh. With score tied 3-3, he rips a two-run double.

Valentin’s line in the game the Sox had to win to extend their season: 2-for-5, one home run, one double, three RBI.

“We were down 2-0 to a club that score a thousand runs this season and he gets the big hits,” said designated hitter Brian Daubach. “And then he comes back the next game and does the same thing.”

Valentin was so hot in Game 4, he was the recipient of the unheard of in Boston. He got a standing ovation after striking out in his fifth at-bat.

This was after he smacked two home runs and two doubles, driving in seven runs in his first four at bats. His first inning home run turned a 1-0 deficit into a 2-1 lead. Boston, behind Valentin, would go on to pummel the Indians 23-5.

“I think Valentin has been the key guy for us,” Red Sox first baseman Mike Stanley said Saturday’s beating of the Yanks. “Both times we needed a key hit against Cleveland he came through. He did the same thing today [Saturday]. We needed to get some runs on the board for Pedro [Martinez] because we didn’t know how healthy he was. John got the big hit again.”

Just as Valentin had done against Cleveland in Game 4, when he followed a Jose Offerman walk with a two-run home run, Valentin followed Offerman’s leadoff triple against Clemens with a towering home-run home run.

“Roger had me 2-2 and I was just thinking, ‘Get the run in somehow,” said Valentin. “He threw me a fastball up and I took a good swing. Next thing I know, it’s in the net.”

Valentin’s line against the Yankees in a game the Sox had to win to make this a series: 3-for-6, one home run, five RBI.

His line through eight playoff games: four home runs and 17 RBI.

“He has some impressive numbers in eight games in these playoffs,” understated Sox manager Jimy Williams.